TW202437034A - Scada web hmi system - Google Patents

Abstract

The present invention provides a SCADA web HMI system comprising: a PLC, HMI client devices and a SCADA server device which are connected via a computer network. The PLC transmits block data relating to a group of field equipments which constitutes an industrial plant, in each period to the SCADA server device. The SCADA server device includes a communication driver which receives the block data; and a client management part which is connected to a plurality of HMI client devices on a one-to-one basis and performs WebSocket communication with each HMI client device. Each of the HMI client devices executes a web browser which shows a HMI screen that is arranged with a parts showing a state of the industrial plant, and each of the HMI client devices updates a state of the parts in response to a signal data received from the client management part. The HMI client device includes a client installer for installing a SCADA web program to be loaded when the browser is started.

Description

SCADA WEB HMI system

The present invention relates to a SCADA WEB HMI system, and more particularly to a technology for reducing the processing load of a large-scale system.

Supervisory Control And Data Acquisition (SCADA) is known as a mechanism for monitoring social infrastructure systems. Social infrastructure systems include steel rolling systems, power transmission and substation systems, water and sewage treatment systems, building management systems, road systems, etc. SCADA is an industrial control system that uses computers to monitor systems, control programs, and collect data. For SCADA, fast responsiveness (real-time) that matches the processing performance of the system is a must.

SCADA is generally composed of the following subsystems.

(1) HMI (Human Machine Interface)

HMI is a mechanism that displays the data of the monitored device to the operator and enables the operator to monitor the monitored device.

(2) Monitoring system

The monitoring system is composed of PLC (Programmable Logic Controller) and other devices. The monitoring system collects data from the monitored device and sends control instructions to the monitored device.

(3) Remote Input Output (RIO)

The remote input and output device is connected to the sensor installed in the monitored device, converts the sensor signal into digital data, and sends the digital data to the monitoring system.

(4) Communication infrastructure

The communication infrastructure connects the monitoring system and remote input and output devices.

As an example of a SCADA HMI subsystem, Patent Document 1 discloses a system having an HMI client and a SCADA server. As in the known SCADA of Patent Document 1, the SCADA server transmits the data (input and output signals, alarm signals) received from the PLC to the HMI client. The input and output signals are signals related to the monitored device (the plant machine group constituting the industrial factory), including actuator control signals and sensor detection signals.

(Prior technical literature)

(Patent Literature)

Patent document 1: Japanese Patent Publication No. 2017-27211

This article will focus on the topic of development of the HMI subsystem, which is one of the subsystems mentioned above.

For large-scale systems, there are cases where the number of signals exchanged between the HMI subsystem and the PLC can reach more than 200,000. In order to process so many signals in real time, the previous SCADA server, which is responsible for monitoring control and data collection, must have a high-performance processor and large-capacity memory. Therefore, there is a demand for an HMI subsystem that can be applied to large-scale systems at a low cost.

In order to realize the low cost of SCADA HMI subsystem, the inventor of this case developed a browser-based SCADA HMI subsystem. In this way, the HMI screen can be realized by a web application running on a web browser.

One advantage of implementing HMI screens on a web browser is that data can be easily obtained from different web servers by switching URLs (including port numbers). That is, historical screen data can be obtained from the online data gathering machine (ODG) that collects and stores all PLC data, and real-time monitoring screen data can be obtained from the SCADA server. By separating the history-related functions that are part of the SCADA function and having the online data gathering machine take charge, the SCADA server can be exclusively responsible for the real-time monitoring function. In order to use low-cost SCADA servers to process a large number of signals, it is hoped that the processing load of input and output signals (including actuator control signals and sensor detection signals) and alarm signals can be reduced.

In large-scale SCADA WEB HMI systems, it is designed in such a way that a plurality of (for example, 128) client machines are connected to one server. In addition, even in a redundant design in which two SCADA servers are set up to distribute the load, a large number of HMI clients are still connected to each SCADA server. When the same HMI screen is displayed on the monitor of each HMI client, the SCADA server must receive the signal data contained in the HMI screen and transmit it to all HMI clients. In the HMI subsystem of the browser-based SCADA, the HMI screen on the HMI client is displayed by a web browser, for example, using a point-to-point connection such as WebSocket, and the signal data is transmitted from the SCADA server to the HMI client. That is, it is not possible to use multicast transmission from the SCADA server to the HMI client. Therefore, when 128 clients are connected to the SCADA server, the SCADA server must transmit 128 times the amount of signal data received to the HMI client. This will cause a large amount of data to flow between the SCADA server and each HMI client during system operation (industrial factory monitoring).

Here, generally speaking, in a network application, it is a program that is downloaded from a SCADA server and executed on a web browser. In other words, the web browser on each HMI client must have a SCADA WEB program that is downloaded from the SCADA server via WebSocket. As shown in FIG. 12 , if the web browser is started on each HMI client before the operation of the system starts, even if the SCADA WEB program is loaded into the web browsers of all HMI clients via WebSocket, the communication volume between the HMI client and the SCADA server is still lower than the communication capacity limit (communication capacity), and will not cause problems in system operation. On the other hand, if the web browser is activated during system operation, communication errors may occur when the communication volume exceeds the communication capacity of the network, or it may take time to load the web page content. This may cause a period of time when the industrial factory cannot be monitored, resulting in problems in system operation.

This invention is developed to solve the above-mentioned problems. Its purpose is to provide a SCADA WEB HMI system that can prevent the communication volume between the HMI client and the SCADA server from exceeding the communication capacity even when a web browser is started during system operation.

The invention of the first aspect of the present disclosure is related to a SCADA WEB HMI system. The SCADA WEB HMI system comprises: a programmable logic controller (hereinafter referred to as PLC), an HMI client, and a SCADA server connected via a computer network. The PLC transmits block data related to a plant machine group constituting an industrial factory to the SCADA server according to a predetermined cycle. The SCADA server comprises: a communication driver for receiving the block data; and a client management unit for connecting to a plurality of the HMI clients in a one-to-one manner and performing WebSocket communication with each HMI client. The aforementioned HMI client is a web browser that respectively executes an HMI screen configured with components that display the status of the aforementioned industrial factory, and updates the status of the aforementioned components based on signal data received from the aforementioned client management unit, thereby monitoring the aforementioned industrial factory. The aforementioned HMI client is equipped with a client installer, and the client installer is used to install the SCADA WEB program to be loaded when the aforementioned web browser is started.

The invention of the second viewpoint is the invention of the first viewpoint and further has the following features. The aforementioned SCADA server is equipped with a client installer that is the same as the aforementioned client installer. Before monitoring the aforementioned industrial factory, the aforementioned client installer is downloaded from the aforementioned SCADA server to the aforementioned HMI client via the aforementioned client management department using the aforementioned web browser.

The invention of the third viewpoint is the invention of the first viewpoint or the second viewpoint and further has the following features. The aforementioned SCADA server is equipped with a communication module, and the communication module contains the content operated by the aforementioned SCADA WEB program. The aforementioned HMI client loads the aforementioned communication module from the aforementioned SCADA server. The aforementioned web browser uses inter-domain communication to exchange data between the aforementioned SCADA WEB program operating in the domain of the aforementioned HMI client and the aforementioned communication module operating in the domain of the aforementioned SCADA server.

The invention of the fourth viewpoint is the invention of the first viewpoint or the second viewpoint and further has the following features. The aforementioned SCADA server downloads application-dependent data and transmits the downloaded aforementioned application-dependent data to the aforementioned HMI client, and the application-dependent data is data dependent on the application that is operated by the aforementioned SCADA WEB program. The aforementioned SCADA server determines whether the aforementioned SCADA WEB program is updated when connected to the aforementioned HMI client, and transmits the aforementioned application-dependent data to the aforementioned HMI client only when it is updated.

The invention of the fifth aspect is the invention of the fourth aspect and further has the following features. The HMI client transmits the version of the application-dependent data of the SCADA WEB program to the SCADA server when the SCADA WEB program is connected to the SCADA server. The SCADA server compares the version received from the HMI client with the version of the downloaded application-dependent data to perform the above-mentioned determination.

According to the present disclosure, a client installer is set on the HMI client, so when the web browser is started, the SCADA WEB program is not loaded from the SCADA server via WebSocket, but is loaded from the HMI client itself. Therefore, even when the web browser is started during system operation, the communication volume between the HMI client and the SCADA server can be prevented from exceeding the communication capacity.

1:SCADA WEB HMI system

2: Programmable logic controller (PLC)

3:SCADA server

31: Communication driver

32: Client Management Department

34: Server Installer

35: Server Program

36: Communication module

37: Application Sending Program

38: Application dependencies

4: HMI client

40: Web browser

40a:Domain

41:HMI screen

42: Parts

43: Client Installer

44:SCADA WEB program

45: Local WEB server

46: Program startup script

5: Computer network

301,401:Processor

302,402:Memory

403: Monitor

303,404: Network interface

405: Input interface

FIG1 is a diagram showing an example of the configuration of a SCADA WEB HMI system for illustrating an implementation of the present invention.

Figure 2(a) is a diagram for explaining the data type of signal data, and Figure 2(b) is a diagram for explaining the identifier.

Figure 3(a) is a diagram for explaining the format of signal data, and Figure 3(b) is a diagram for explaining the format of screen update data.

Figure 4 is a diagram used to illustrate the processing of the client management department of the SCADA server.

Figure 5 is a diagram used to illustrate how to load the SCADA WEB program.

Figure 6 is a diagram used to illustrate the client installer being sent to the HMI client in advance.

Figure 7 is a diagram used to illustrate how to load the communication module.

Figure 8 is a diagram used to illustrate another way to load the communication module.

Figure 9 is a diagram used to illustrate how application dependent data is loaded.

Figure 10 is a flow chart for illustrating a method for loading application dependent data.

Figure 11 is a block diagram showing an example of the hardware configuration of a SCADA server and an HMI client.

Figure 12 is a diagram used to illustrate the learning topic.

The following is a detailed description of the implementation of the present invention with reference to the drawings. Here, the same symbols are attached to the common elements in each figure and repeated descriptions are omitted.

1-1.SCADA WEB HMI system

FIG. 1 is a diagram for explaining an example of the configuration of a SCADA WEB HMI system of implementation type 1. The SCADA WEB HMI system 1 shown in FIG. 1 includes: a PLC 2, a SCADA server 3, and an HMI client 4 connected to each other via a computer network 5. The computer network 5 is, for example, Ethernet (registered trademark). The SCADA WEB HMI system 1 may also include an online data gathering machine (ODG: Online Data Gathering) which is omitted in the figure.

PLC 2 is connected to a group of plant machines (including actuators and sensors) constituting an industrial factory via a control network omitted in the diagram. PLC 2 transmits packets containing block data to computer network 5 in a multicast or broadcast manner at a predetermined period. Block data is a collection of PLC signals. One block data contains tens to hundreds of PLC signals. The types of PLC signals include input and output signals (including actuator control signals and sensor detection signals) and warning signals. Block data includes at least one of a collection of input and output signals and a collection of alarm signals. The total number of alarm signals is less than the total number of input and output signals.

Block data is transmitted periodically regardless of whether the value of the PLC signal has changed from the previous value. Therefore, even if the packet containing the transmitted block data is lost, it will be transmitted again in the next transmission cycle, so that the latest status can be reflected in the SCADA server 3 and the online data collector.

The SCADA server 3 includes a communication driver 31 and a client management unit 32. The communication driver 31 is configured to receive block data from the PLC 2 at a predetermined period, and to perform unpacking to decompose the received block data into signal data according to the data type. As for the data type, in addition to the bit type shown in FIG. 2(a), short type or float type can also be used. Furthermore, the communication driver 31 is configured to perform packet processing, which adds a corresponding signal data identifier to each signal data (refer to FIG. 2(b)) to generate a packet according to the data type, and transmits the generated packet to the client management unit 32. That is, the signal data transmitted from the communication driver 31 to the client management unit 32 is a pair of the signal data identifier and the value of the signal data (refer to Figure 3(a)).

Here, the signal data identifier corresponds to the text string written by the application programmer. The data size of the signal data identifier is, for example, 23 bits. In this way, the signal data identifier can represent about 8 million signal data and can fully correspond to the large-scale SCADA WEB HMI system 1. If it is bit type data, since the signal data identifier is 23 bits and the data value is 1 bit, the data size of each signal is 24 bits (= 3 bytes). If it is float type data, since the signal data identifier is 23 bits and the data value is 4 bytes, 1 bit of padding is added, and the data size of each signal is 7 bytes. In addition, it can also be set so that when generating a packet, only the signal data related to the signal data identifier currently displayed on the HMI screen 41 of the web browser 40 is extracted.

The client management unit 32 has: a signal data receiving thread, at least one signal data buffer, and a signal data transmitting thread. The signal data receiving thread receives packets (signal data according to the data type) received from the communication driver 31 and stores the signal data in the signal data buffer. The signal data buffer has an area (array) for storing signal data according to the data type. Assuming that there are 8 million signal data, if the text type is excluded, the memory usage is about 24Mbyte. Therefore, considering the current computer specifications, it can be said that the memory usage will not cause problems. Moreover, by using the index, the amount of data stored in the signal data buffer can be reduced. When the signal data transmission thread receives an instruction from the signal data reception thread, it reads the signal data stored in the signal data buffer and transmits the read signal data to the HMI client 4 according to the data type. At this time, the screen identifier and the product identifier of the display HMI screen 41 and the product (component) 42 shown in Figure 3 (b), and the updated signal data are transmitted to the HMI client 4 as screen update data (refer to Figure 4). As shown in Figures 2 to 4, by binarizing the signal data, the amount of data transmitted to the HMI client 4 can be reduced.

As shown in FIG. 11 described later, the SCADA server 3 is equipped with: a processor 301 for executing various processes; a memory 302 for storing various data; and a network interface 303. The processor 301 executes the program stored in the memory 302, thereby constituting the various processes described above and below.

The HMI client 4 has a processor 401, a memory 402, a monitor 403, a network interface 404, and an input interface 405 as shown in FIG. 11 described later. The processor 401 executes the program stored in the memory 402, whereby the processor 401 is configured to execute a web browser 40, which displays an HMI screen (screen) 41 configured with a display component. The monitor 403 displays the web browser 40.

The web browser 40 switches the connection destination (SCADA server 3, online data collection machine) according to the URL, and can obtain various information of the HTML document related to the HMI screen 41 from the WEB server specified by the URL. The HMI screen 41 includes a monitoring screen that is required to be real-time and a historical screen that displays historical data.

When the screen 41 currently displayed on the web browser 40 is a monitoring screen, the web browser 40 changes the display state of the display component 42 according to the input/output signal received from the SCADA server 3. The change of the display state refers to, for example, a change in a value, text, color, or shape. In addition, the web browser 40 changes the display state of the alarm component 42 configured on the HMI screen 41 according to the alarm signal received from the SCADA server 3.

When the screen 41 currently displayed on the web browser 40 is a historical screen, the web browser 40 requests historical data from the online data collector. The web browser 40 displays the historical data received from the online data collector on the historical screen.

Although not shown in the figure, the online data collector has a processor and a memory. The processor executes the program stored in the memory, whereby the processor is configured to execute Web server processing and historical data management processing. The online data collector receives block data periodically from PLC 2. The historical data management processing of the online data collector stores the historical data of all signals contained in the received block data in the memory (including the database). The Web server processing of the online data collector transmits historical data based on the request from the web browser 40. In addition, the online data collector receives the alarm packet from the SCADA server 3 and stores it.

1-2. How to load SCADA WEB program

FIG5 is a diagram for explaining the loading method of the SCADA WEB program. As shown in FIG5, the HMI client 4 is equipped with a client installer 43. The client installer 43 is operated at the time of updating the SCADA WEB program, and the local WEB server 45 and the SCADA WEB program 44 are configured on the client 4. The web browser 40 can load the SCADA WEB program through the local WEB server 45 when it is started. In this way, unlike the known situation of loading the SCADA WEB program 44 from the SCADA server 3, the communication bandwidth between the HMI client 4 and the SCADA server 3 is completely allocated to the communication traffic during system operation.

The installation method of the client installer 43 for the HMI client 4 can also adopt CD-ROM, but as shown in FIG6, if it is configured to be sent in advance (HTTP loading) from the SCADA server 3 to the HMI client 4, the time and effort for installing the client installer 43 will be saved, thereby suppressing the operation cost. That is, the SCADA server 3 is equipped with the client installer 43. The client installer 43 includes: a local WEB server 45 operating on the client 4, a SCADA WEB program 44, and a SCADA WEB program startup script 46. In this way, the system operation administrator can download the client installer 43 from the SCADA server 3 using only a web browser 40. Furthermore, when the client installer 43 is executed on the HMI client 4, the local WEB server 45 is started on the HMI client 4, and the SCADA WEB program 44 and the SCADA WEB program activation script 46 are configured on the client 4. At this time, a shortcut linked to the SCADA WEB program activation script 46 is configured on the Windows (registered trademark) desktop in the monitor 403, so the operator only needs to double click the shortcut, and the SCADA WEB program 44 will be loaded on the web browser 40. The SCADA WEB program startup script 46 also includes the communication address of the SCADA server 3. The SCADA WEB program 44 will automatically connect to the SCADA server 3, and the operator can immediately start monitoring the system.

1-3. How to load the communication module

Figure 7 is a diagram for explaining a method of loading a communication module. Figure 8 is a diagram for explaining another method of loading a communication module.

The communication module 36 provides the functions required for the SCADA WEB program 44 to communicate with the server. This type of communication module 36 is not loaded from the local WEB server 45, but must be loaded from the SCADA server 3. The SCADA server 3 is equipped with a server installer 34. When the server installer 34 is started, the server program 35 and the communication module 36 are configured on the SCADA server 3. The communication module 36 needs to communicate with the client management unit 32 on the SCADA server 3 via WebSocket, but due to security reasons such as the so-called same-origin policy, it must operate in the domain 40b of the SCADA server 3. In other words, the communication module 36 must be loaded from the client management unit 32 on the SCADA server 3. Therefore, as shown in FIG7, the SCADA WEB program 44 operating in the domain 40a of the HMI client 4 on the web browser 40 and the communication module 36 operating in the domain 40b of the SCADA server 3 use inter-domain communication for data exchange. Another method is to set CORS (Cross Domain Resource Sharing) for the SCADA server 3 as shown in FIG8, so that it can accept communication connections from other domains, so that the communication module 36 can also be installed in the HMI client 4 in advance. In this way, the communication load between the HMI client 4 and the SCADA server 3 can be further reduced.

1-4. How to load application dependent data

FIG. 9 is a diagram for explaining the method of loading application-dependent data. FIG. 10 is a flow chart for explaining the method of loading application-dependent data.

In order to operate the SCADA WEB program 44, the application-dependent data 38 that the application depends on must also be loaded onto the web browser 40. The application-dependent data 38 is downloaded to the SCADA server 3 by the application delivery program 37. The application-dependent data 38 includes the application version (revision), and as described later, is sent to the HMI client 4 only when there is an update. At the time when the SCADA WEB program 44 is connected to the client management unit 32 on the HMI client 4, the routine shown in FIG. 10 is started. According to this routine, the SCADA WEB program 44 sends the application version of the application-dependent data 38 currently held to the SCADA server 3 (step S1). The SCADA server 3 compares the application version of the downloaded application dependency data 38 with the application version transmitted in step S1 (step S2). As a result of the comparison, if the application versions are the same, the SCADA server 3 transmits the subject that the application dependency data 38 has not been updated to the SCADA WEB program 44 (step S3). Afterwards, the SCADA WEB program 44 uses the retained application dependency data 38 (step S4) and ends this routine.

On the other hand, when the application version is different, that is, when the application dependency data 38 is updated, the SCADA server 3 transmits the new application dependency data 38 to the SCADA WEB program 44 (step S5). Afterwards, the SCADA WEB program 44 retains and uses the transmitted application dependency data 38 (step S6), and ends this routine.

If the application is not updated, the application dependency data 38 will not be changed. Therefore, the application dependency data 38 once transmitted to the HMI client 4 is first saved on the HMI client 4 side, and only when the application is updated, the application dependency data 38 is transmitted to the HMI client 4, thereby reducing the communication load between the HMI client 4 and the SCADA server 3.

1-5. Effects

As described above, according to this embodiment, the client installer 43 is set on the HMI client 4, so when the web browser 40 is started, the SCADA WEB program 44 is not loaded from the SCADA server 3 via HTTP, but loaded from the HMI client 4 itself. Therefore, even when the web browser 40 is started during system operation, the communication volume between the HMI client 4 and the SCADA server 3 can be prevented from exceeding the communication capacity. In this way, communication errors can be prevented from occurring during system operation, or time is wasted on loading web page content, and the time when industrial factories cannot monitor can be eliminated.

2. Hardware configuration example

FIG11 is a block diagram showing an example of the hardware configuration of the SCADA server 3 and the HMI client 4.

Each processing of the above-mentioned SCADA server 3 is realized by a processing circuit. The processing circuit is composed of a processor 301, a memory 302, and a network interface 303. The processor 301 realizes each function of the SCADA server 3 by executing various programs stored in the memory 302. The memory 302 includes a main memory device and an auxiliary memory device.

Each processing of the above-mentioned HMI client 4 is realized by a processing circuit. The processing circuit is composed of a processor 401, a memory 402, at least one monitor 403, a network interface 404, and an input interface 405. The processor 401 realizes each function of the HMI client 4 by executing various programs stored in the memory 402. The memory 402 includes a main memory device and an auxiliary memory device. The input interface 405 is an input device such as a keyboard, a mouse, a touch panel, etc. Multiple monitors 403 can also be set.

The above has described the implementation of the present invention, but the present invention is not limited to the above implementation, and can be implemented in various ways without departing from the gist of the present invention. In the above implementation, the number, quantity, amount, range, etc. of each component element is mentioned. Except for the case where it is specifically stated or the case where it is clearly limited to the number in principle, the present invention is not limited to the number mentioned. In addition, the structure described in the above implementation is not a necessary structure of the present invention, except for the case where it is specifically stated or the case where it is clearly limited to the structure in principle.

3:SCADA server

32: Client Management Department

34: Server Installer

35: Server Program

4: HMI client

40: Web browser

43: Client Installer

44:SCADA WEB program

45: Local WEB server

Claims (4)

A SCADA WEB HMI system comprises: a plurality of programmable logic controllers (hereinafter referred to as PLCs), a plurality of HMI clients and a SCADA server connected via a computer network; wherein, The aforementioned PLC transmits block data related to the plant machine cluster constituting the industrial factory to the aforementioned SCADA server at a predetermined period; The aforementioned SCADA server is equipped with: a communication driver for receiving the aforementioned block data; and a client management unit for connecting to a plurality of aforementioned HMI clients in a one-to-one manner and performing WebSocket communication with each HMI client; The aforementioned HMI client machines respectively execute web browsers configured with HMI screens of components displaying the status of the aforementioned industrial factories, and update the status of the aforementioned components according to the signal data received from the aforementioned client management unit, thereby monitoring the aforementioned industrial factories; wherein, The aforementioned HMI client is equipped with a client installer, which is used to install the SCADA WEB program to be loaded when the aforementioned web browser is started; The aforementioned SCADA server downloads application-dependent data and transmits the downloaded application-dependent data to the aforementioned HMI client. The application-dependent data is data that is dependent on the application that is operated by the aforementioned SCADA WEB program; When the SCADA server is connected to the HMI client, it determines whether the SCADA WEB program is updated, and only transmits the application dependent data to the HMI client if it is updated. The SCADA WEB HMI system as described in claim 1, wherein the aforementioned SCADA server has a client installer that is the same as the aforementioned client installer; Before monitoring the aforementioned industrial factory, use the aforementioned web browser to download the aforementioned client installer from the aforementioned SCADA server to the aforementioned HMI client via the aforementioned client management department. A SCADA WEB HMI system as described in claim 1 or 2, wherein the SCADA server is provided with a communication module, and the communication module includes content for actions performed by the SCADA WEB program, The aforementioned HMI client loads the aforementioned communication module from the aforementioned SCADA server. The aforementioned web browser uses inter-domain communication to exchange data between the aforementioned SCADA WEB program operating in the domain of the aforementioned HMI client machine and the aforementioned communication module operating in the domain of the aforementioned SCADA server. The SCADA WEB HMI system as described in claim 1, wherein: The aforementioned HMI client transmits the revision of the aforementioned application-dependent data of the aforementioned SCADA WEB program to the aforementioned SCADA server when the aforementioned SCADA WEB program is connected to the aforementioned SCADA server; The aforementioned SCADA server compares the aforementioned version received from the aforementioned HMI client with the version of the aforementioned application dependent data downloaded to perform the aforementioned determination.

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